The present invention relates generally to equipment utilized in operations in subterranean wells and, in an embodiment described herein, more particularly provides a wye block apparatus having a rotary guide incorporated therein.
It is well known in the art to provide a wye block where access to more than one wellbore or portion of a wellbore is desired. For example, where a lateral wellbore has been drilled intersecting a parent wellbore, it is sometimes desirable to install a tubing string into the lateral wellbore, install another tubing string into the parent wellbore below the intersection of the lateral and parent wellbores, and to connect these to a tubing .string extending upward through the parent wellbore and to the earth's surface. An item of equipment which permits interconnection of these three tubing strings is known as a wye block.
One form of a wye block apparatus which permits selective re-entry into a lateral or lower parent wellbore is disclosed in U.S. Pat. No. 5,427,177, the disclosure of which is incorporated herein by this reference. This wye block apparatus includes a flapper which is rotated about a lateral axis in order to provide selective access to either of two lower wellbores. Unfortunately, this design requires the flapper to rotate about a pin installed laterally between two lower openings, and also requires the upper end of the flapper to sweep laterally across the interior of the wye block apparatus. Consequently, this apparatus is sensitive to debris, which may cause the apparatus to malfunction, thereby deleteriously prohibiting access to one or more of the lower wellbores.
From the foregoing, it can be seen that it would be quite desirable to provide a wye block apparatus which is not sensitive to debris therein, which does not have a member that must sweep laterally across the interior of the apparatus, and which does not require complex mechanisms for its operation, but which is convenient in its operation. It is accordingly an object of the present invention to provide such a wye block apparatus.